Compounds where the hydrogen of the 2′ hydroxyl group in 2,2′-binaphthol-3-aldehyde is selectively substituted are used for various uses. Among such compounds, the compound of the following formula 6, which is very useful for separating chiral amino alcohols or amino acids into their respective optical isomers by recognizing their chirality through an imine bond or for converting L-amino acid into D-amino acid or D-amino acid into L-amino acid, has been developed by the inventors of the present invention and patented (Korean Patent No. 0661280).

However, according to the prior art where the hydrogen of the 2′ hydroxyl group in 2,2′-binaphthol-3-aldehyde is substituted, a mixed product of a compound where the hydrogen of the 2 hydroxyl group is substituted and a compound where the hydrogen of the 2′ hydroxyl group is substituted is obtained because of the low selectivity for the 2′ hydroxyl group. In particular, compounds where the hydrogen of the 2 hydroxyl group is substituted are obtained in more amounts. Such mixed product has a problem that the efficiency for preparing the target product is greatly deteriorated because the mixture cannot be easily separated, and thus there is a difficulty such as that the alkylation process must be carried out after protecting the 2 hydroxyl group with a protecting group to achieve substitution of the hydrogen of the 2′ hydroxyl group. Thus, a technology for increasing the selectivity for hydrogen of the 2′ hydroxyl group, which prevents byproducts from being generated, is required.
Meanwhile, the novel compounds of the present invention, binaphthol derivatives, are represented by the following formula 1, and for the preparation of said compound, the compound of the following formula 2 can be used.

Also, the starting material used in prior art, enantiomerically pure binaphthol, is relatively expensive. Thus, it is necessary to develop a method for preparing enantiomerically pure binaphthol derivatives using cheaper materials.